repo sync | baa3858 | 2013-07-26 17:53:31 -0700 | [diff] [blame] | 1 | /* Ppmd7Enc.c -- PPMdH Encoder
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| 2 | 2010-03-12 : Igor Pavlov : Public domain
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| 3 | This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
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| 4 |
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| 5 | #include "Ppmd7.h"
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| 6 |
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| 7 | #define kTopValue (1 << 24)
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| 8 |
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| 9 | void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p)
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| 10 | {
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| 11 | p->Low = 0;
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| 12 | p->Range = 0xFFFFFFFF;
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| 13 | p->Cache = 0;
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| 14 | p->CacheSize = 1;
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| 15 | }
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| 16 |
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| 17 | static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p)
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| 18 | {
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| 19 | if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0)
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| 20 | {
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| 21 | Byte temp = p->Cache;
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| 22 | do
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| 23 | {
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| 24 | p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32)));
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| 25 | temp = 0xFF;
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| 26 | }
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| 27 | while(--p->CacheSize != 0);
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| 28 | p->Cache = (Byte)((UInt32)p->Low >> 24);
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| 29 | }
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| 30 | p->CacheSize++;
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| 31 | p->Low = (UInt32)p->Low << 8;
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| 32 | }
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| 33 |
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| 34 | static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total)
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| 35 | {
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| 36 | p->Low += start * (p->Range /= total);
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| 37 | p->Range *= size;
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| 38 | while (p->Range < kTopValue)
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| 39 | {
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| 40 | p->Range <<= 8;
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| 41 | RangeEnc_ShiftLow(p);
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| 42 | }
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| 43 | }
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| 44 |
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| 45 | static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0)
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| 46 | {
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| 47 | p->Range = (p->Range >> 14) * size0;
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| 48 | while (p->Range < kTopValue)
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| 49 | {
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| 50 | p->Range <<= 8;
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| 51 | RangeEnc_ShiftLow(p);
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| 52 | }
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| 53 | }
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| 54 |
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| 55 | static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0)
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| 56 | {
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| 57 | UInt32 newBound = (p->Range >> 14) * size0;
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| 58 | p->Low += newBound;
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| 59 | p->Range -= newBound;
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| 60 | while (p->Range < kTopValue)
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| 61 | {
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| 62 | p->Range <<= 8;
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| 63 | RangeEnc_ShiftLow(p);
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| 64 | }
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| 65 | }
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| 66 |
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| 67 | void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p)
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| 68 | {
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| 69 | unsigned i;
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| 70 | for (i = 0; i < 5; i++)
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| 71 | RangeEnc_ShiftLow(p);
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| 72 | }
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| 73 |
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| 74 |
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| 75 | #define MASK(sym) ((signed char *)charMask)[sym]
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| 76 |
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| 77 | void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol)
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| 78 | {
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| 79 | size_t charMask[256 / sizeof(size_t)];
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| 80 | if (p->MinContext->NumStats != 1)
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| 81 | {
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| 82 | CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext);
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| 83 | UInt32 sum;
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| 84 | unsigned i;
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| 85 | if (s->Symbol == symbol)
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| 86 | {
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| 87 | RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq);
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| 88 | p->FoundState = s;
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| 89 | Ppmd7_Update1_0(p);
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| 90 | return;
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| 91 | }
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| 92 | p->PrevSuccess = 0;
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| 93 | sum = s->Freq;
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| 94 | i = p->MinContext->NumStats - 1;
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| 95 | do
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| 96 | {
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| 97 | if ((++s)->Symbol == symbol)
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| 98 | {
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| 99 | RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq);
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| 100 | p->FoundState = s;
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| 101 | Ppmd7_Update1(p);
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| 102 | return;
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| 103 | }
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| 104 | sum += s->Freq;
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| 105 | }
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| 106 | while (--i);
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| 107 |
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| 108 | p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol];
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| 109 | PPMD_SetAllBitsIn256Bytes(charMask);
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| 110 | MASK(s->Symbol) = 0;
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| 111 | i = p->MinContext->NumStats - 1;
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| 112 | do { MASK((--s)->Symbol) = 0; } while (--i);
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| 113 | RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq);
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| 114 | }
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| 115 | else
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| 116 | {
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| 117 | UInt16 *prob = Ppmd7_GetBinSumm(p);
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| 118 | CPpmd_State *s = Ppmd7Context_OneState(p->MinContext);
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| 119 | if (s->Symbol == symbol)
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| 120 | {
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| 121 | RangeEnc_EncodeBit_0(rc, *prob);
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| 122 | *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
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| 123 | p->FoundState = s;
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| 124 | Ppmd7_UpdateBin(p);
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| 125 | return;
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| 126 | }
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| 127 | else
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| 128 | {
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| 129 | RangeEnc_EncodeBit_1(rc, *prob);
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| 130 | *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
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| 131 | p->InitEsc = PPMD7_kExpEscape[*prob >> 10];
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| 132 | PPMD_SetAllBitsIn256Bytes(charMask);
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| 133 | MASK(s->Symbol) = 0;
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| 134 | p->PrevSuccess = 0;
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| 135 | }
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| 136 | }
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| 137 | for (;;)
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| 138 | {
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| 139 | UInt32 escFreq;
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| 140 | CPpmd_See *see;
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| 141 | CPpmd_State *s;
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| 142 | UInt32 sum;
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| 143 | unsigned i, numMasked = p->MinContext->NumStats;
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| 144 | do
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| 145 | {
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| 146 | p->OrderFall++;
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| 147 | if (!p->MinContext->Suffix)
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| 148 | return; /* EndMarker (symbol = -1) */
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| 149 | p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix);
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| 150 | }
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| 151 | while (p->MinContext->NumStats == numMasked);
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| 152 |
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| 153 | see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq);
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| 154 | s = Ppmd7_GetStats(p, p->MinContext);
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| 155 | sum = 0;
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| 156 | i = p->MinContext->NumStats;
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| 157 | do
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| 158 | {
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| 159 | int cur = s->Symbol;
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| 160 | if (cur == symbol)
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| 161 | {
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| 162 | UInt32 low = sum;
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| 163 | CPpmd_State *s1 = s;
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| 164 | do
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| 165 | {
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| 166 | sum += (s->Freq & (int)(MASK(s->Symbol)));
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| 167 | s++;
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| 168 | }
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| 169 | while (--i);
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| 170 | RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq);
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| 171 | Ppmd_See_Update(see);
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| 172 | p->FoundState = s1;
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| 173 | Ppmd7_Update2(p);
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| 174 | return;
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| 175 | }
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| 176 | sum += (s->Freq & (int)(MASK(cur)));
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| 177 | MASK(cur) = 0;
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| 178 | s++;
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| 179 | }
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| 180 | while (--i);
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| 181 |
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| 182 | RangeEnc_Encode(rc, sum, escFreq, sum + escFreq);
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| 183 | see->Summ = (UInt16)(see->Summ + sum + escFreq);
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| 184 | }
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| 185 | }
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